Rotary cutting die for perforating signatures



Nov. 6, 1956 l. SPINNER ROTARY CUTTING DIE FOR PERFORATING OF'SIGNATURES Fl-led Nov. 2 3, 1951 2 Sheets-Sheet l INVENTOR.

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l. sPlNNER 2,769,496 ROTARY CUTTING DIE FOR PERFORATING OF' SIGNATURESNov. 6, 1956 2 Sheets-Sheet 2 Flled Nov. 25,A 1951 e 6 INVEMTOR.

Isidore Spinner BY United States Patent ROTARY CUTTING DIE FORPERFORATING SIGNATURES Isidore Spinner, Chicago, lll.

Application November 23, 19.51, Serial No. 257,700 Claims. (Cl. 164-99)This invention relatesrto the book making art. More particularly, itrelates to books of the type comprising one or more signatures the pagesof which are secured together and to a cover by adhesive, withoutstitching, stapling or the like.

In my co-pending applications Serial Nos. 185,897, led September 20,1950, now abandoned, and 242,534, filed August 18, 1951, there isdisclosed a method of making a book of the type with which the presentinvention is concerned, wherein each signature has a series of alignedslots formed at the fold thereof and into which glue or other adhesiveenters for securing the sheets of the signature together. Consider asignature wherein the gluereceiving slots are of a generally rectangularshape. Those slots may have to be of an appreciable width to providevthe required glue-holding areas, and for other reasons, in the case ofbooks that have a comparatively long, useful life as distinguished frompamphlets, magazines or the like. Also, in books wherein the pages areof appreciable thickness and where it is desired that each signatureconstitute a large number of pages, it is necessary that Ithe series oflongitudinal slots at the fold be of appreciable width. In all books itis necessary that the fold line be centered with respect to therespective aligned adhesivereceiving slots. In the making of thesignature the last fold is made after formation of the aligned slotsthat are t0 be centered on the fold. When the fold is made after theslots have been formed there is a tendency in many instances for theline of fold to form off center with respect to the aligned slots. Thisis objectionable not only because it results in relative misalignment ofthe printing matter on the respective pages, but also, it reduces theholding action of the adhesive insofar as concerns some of the pages.

It is one of the objects of the present invention to provide a means forproducing the last fold in the perforated or slotted signature whereinthe fold will naturally form centrally of the series of slots. In thepreferred embodiment of the present invention this result is obtained byforming in each hinge portion between adjacent slots one or morecentrally located weakened portions that may comprise pin holeperforations or may comprise a short longitudinally extending slit inthetab between adjacent slots, each slit being of a length appreciably lessthan the spacing between adjacent slots in the signature.

It is a further object of the present invention to provide a cutter forforming the glue-receiving slots in the signature, which cutter willalso form the fold facilitating weakened portions so that in theformation of the signature it is assured that the weakened portions willbe properly located with respect to the slots. This eliminates the needfor extreme precision in alignment of the mechanisms such as would benecessary if the slot forming perforator and the weakening mechanismwere different mechanical parts to perform their operationssuccessively.

The attainment of the above and further objects of Patented Nov. 6, 1956ICC the present invention will be apparent from the followingspecification taken in conjunction with the accompanying drawingsforming a part thereof.

In the drawings:

Figures 1, 2 and 3 are views of a sheet of printed pages in successivestages in the process of folding to form a signature;

Figure 4 is a perspective view of a portion of a folding machine whereinthe slots are formed immediately before the last fold is formed in thesignature;

Figure 5 is a longitudinal sectional View through the cutter and thecutter guide assembly;

Figmres 6 and 7 are fragmentary views showing the movement of the cutterteeth through the signature in making the row of slots in the signature;

Figure 8 is a perspective view of a portion of the cutter guide cagethat guides the cutter and through which the cut-away paper moves;

Figure 9 is a perspective view of a fragmentary portion of the malecutter ring of the present invention;

Figure 10 is an enlarged View illustrating the action of the cutterteeth on the paper in forming the slots;

Figure ll is a fragmentary sectional view taken along the line 1].-11 ofFigure 10 and looking in the direction of the arrows;

Figure 12 is a perspective View of a fragmentary portion of a modifiedform of the male cutter ring of the present invention;

Figures 13 and 14 are enlarged perspective views illustrating the slotsand cuts formed in the signature by the cutters of Figures 9 and 12,respectively;

Figure 15 is an enlarged fragmentary perspective View through a portionof the signature at a fold, illustrating the insertion of an auxiliarypage or sheet thereinto;

Figure 16 is a fragmentary perspective View of a stack of signaturespreparatory to the application of a cover thereto; and

Figures 17 and 18 are enlarged fragmentary transverse sectional viewsthrough two diiferent books bound in different ways and embodying thesignatures of the present invention, the sections being taken through aslotted portion of the book in each case.

Reference may now be had more particularly to the drawings wherein likereference numerals designate like parts throughout.

In Figures l, 2 and 3 there is shown at 1 a sheet of paper havingprinted matter 2 thereon on both sides thereof and in such relationshipthat when the sheet is properly folded to form the signatures theprinted pages will appear in the correct sequences. The sheetillustrated in Figure l, for instance, contains sixteen pages of printedmatter, eight on each side. The sheet 1 is folded along a dotted line 3to produce the sheet of Figure 2. TheV folded sheet of Figure 2 is thenperforated to produce a series of discontinuous perforations 4 spacedapart and in alignment centrally of the sheet. The perforations 4 are inthe line of the next fold to be made and are for the purpose offacilitating the escape of air from between the layers of the sheet inthe next folding operation, as is known in the art. These perforationsdo not involve the removal of paperk from the partially folded signatureand, per se, form no part of the present invention. The sheet of Figure2 is then folded along the line 4 to produce the signature ofV Figure 3,which signature has yet to receive one additional fold. The nextoperation consists in forming aligned slots 5-5, of rectangular shape,each slot being formed by the actual removal of paper from thesignature. The slots 5 are in alignment and are spaced apart byunslotted portions 6 of the signatur'e, which unslotted portions thenform hinges for the next or last folding operation of the signature. Theslots advances to, a final set of folding rollers where are of anydesired size for the purpose intended, which will be more fully setforth as this description'proceeds, it'being sufiicient for thepresentttoV state that the slots Y are, in one construction,approximately 17716 of an inch` long, about 1/32 of an inch wide,'andabout 1A of an inch apart. The last fold of the signature is formed on aline passing lengthwise through the aligned slots 5, as is illus` tratedin Figure 4. Y

Reference may now lbe had more particularly to Figure 4 that shows afragmentary portion of one conventional type ofY folding machine,namely, the Cleveland folder, to which the present invention is applied.in this Well VVknown type of machine the sheet of paper of Figure ladvances to a first set of folding rollers that fold it along the line 3to produce the structure of Figure 2, and then advance. to aV Vsecondset of folding rollers that fold it Y Y along the line 4 of Figure 2 toproduce the almost comfolded signature of Figure 3, and then the paper`The rotary cutting punch assembly includes a collar 2S that is keyed tothe shaft as by a set screuI 29. The

rcollar includes a neck 32 externally threaded as at 34 and having acircular portion 36 that terminates at a shoulder 3S for receiving arotary cutting die 40. The cutting die is in the formiof a circular orring-like disc which will be more fullyl described as thisspecifi-cation proceeds. The disc rests Von the shoulder 38 of thecollar 23 and is clamped in pla-ce by a ring 42 that rests on the rotarycutting die 49 and is clamped thereagainst by a nut Lil'li'threaded onthe external threads 34 of the neck 32. The nut 44 is of Va cylindricalexternal shape and of the same external diameter as arethe rollers 23and 24. ,Y

On the shaft 2l there is mounted a cage 50 as by a set` screw Si. Thecage Stl'constitutes a backing die for the' cutting die or punchassembly 26. The cage 50 is of cylindrical shape and includes a bottomroller portion 52, intermediate openings 53 and an upper guiding edge54L At the inside of the cage 50 the collar portion 52 has an upwardlyextending frusto conical projection 56y which flares outwardly, so thatpaper cuttings within the cage will be guided downwardly and outwardlythrough the openings S3. The upperv inner surface of the cage 50 t istapered to a narrow thickness at 54 to constituteV a support for theteeth of the rotary cutter 40 during operation of the machine tominimize any respective teeth Vto be bent. Y

Above the cage 50 there is mounted Vagcylindrical collar f 69 as by aset screw 6l.V Theunder side of this collar t has a frusto conical bore63 that terminates in a narrow guiding edge'and of the same diameter asthat of the cage Si) and located above the guiding edge 54 an amountslightly in excess of the VVthickness of the teeth of the Y rotarycutter.

Lower and upper rollers 66-.67 are secured to the shaft 2l, as by setscrews, in Vpositions opposite vthe rollers 23--24 for guiding thesignature as it moves between the two shafts into a position whereit'is'perforated.

tendency for the All the rollers thus far described, on the shaftr20,are

vof the same diameters and all the rollers thus far descrihcd, on theshaft V21, are of the same diameters One Y of the two shafts, preferablythershaft 20, ismotor driven, and the shaft 2l is driven by'frictionalVengagement with the rollers on the motor driven shaft.V The'shafts 20and Z1 may be of considerable length and it is desired that there shallbe no variation in the separation of the shafts. They may therefore bebraced .with respect to one another.

t The direction of rotation of the shaft 20k is such asto tend totighten the nut 44 on its threaded collar 32..

An explanation will now bev given of the construction and operation ofthe cutter 40. The cutter 40cornpris'es an annular disc of diesteelhaving a ring portion 82 from which project a number of identical,uniformly spaced teeth 84. Each tooth 84' is in effect a punch havingtwo cutting edges 86 and S7 at an angle to one another forming a leadingcutting edge 88 and a trailing cutting edgeV i 89. The edges 88 and 89are'so located with respect to one another that in the rotation of thecutter both edges 88 and S9 strike the outer surface of the stack ofpaper at almost the same time, or with the edge S3 engaging the paperslightly before the edge 8,9. The paper is being advanced in thedirection indicated by the arrow 90 due to the rolling action of therollers 24, 44, 28V and 23 (Fig. 5) all of which are of .the samediameter. j Asthe cutter and the paper continue to advance after theedge 88 has engaged the paper, theV edge 88 of the cutter toothY firstexesand then tears or cuts the paper and the cuttingV edge S6 followsand produces some cutting or punching action before the edge 89 engagesthe top Sheet of the A.

partially formed signature 10. Thereafter, as the paper and the cuttertooth Icontinue to move, there is a continuation of the advance of thecutting edge 86 and the cutting edge 87 into the stack of the paper 10,with the uncut paper portion between the cutting edges 86 Vand 87becoming progressively smalle'rtin length by an action wherein thecutting edge 87 is cutting towards'the cutting edge 86. When theY cuttertooth S4 reaches its innermost position in the signature the slot 5 hasbeen formed in the paper and the edges of the individual sheets at theslot are flexed slightly inta direction downwardly asseen in Figure Vl0,the exure at the leading edge being indicated at 92 and at the trailingedge being indicated at 93.? VAs 'the movement of the -cutter and theVpaper continues, the

Vedge 94 Yof the cutter toothforces the flexed edge of the slot at V92downwardly as seen at 96 in Figure 10, so that the paper at 96 at theedge of each slot is flexed outwardly to form a short projection. showngreatly exaggerated to facilitate illustration.V The projection 96 yisutilized in thel binding of a book of which theV signature is one of thecomponent parts, as will be Y more fully explainedas this descriptionproceeds.

It is to be'noted that the-trailing'side of each cutter Vtooth 84 has asurface Sla which is inclined with respect to theradial axis of thetooth.Y It is this inclined siu'face 84 Ywhich causes a slight spreadingaction of the trailing edge of each slot. Because of the fact that theteeth completely penetrate allrthe thicknesses of paper of the signatureand because of the fact that the radial extent of the teeth is greaterthan the radial extent of the kpe- .riphery of the driving rolls, therate of the tangential component of motion or sweep of the teeth'passing through the slot is greater than the rate of travel of the'paper signature and this in a large measure accounts for the spreadingaction wherein the leading ends of the slots are deformed outwardly. f

From the description thus far given it is apparent that during thecutting action of .the -cutter the paper is removed by the actionof thetwo :cutting edgesrand 87 moving Ytowards one another.` As the paper isbeing cut at each slot the cut edges of the paper are being pushedprogressively through the slot so that when all of the guided by theVrotating frusto conical portion"56 to the outside of the cage, bytheaction of centrifugal force, Y

through the openings 53. The chips maybe drawn off by` any vacuum orsuction system. During the cutting action the'paper is held Vbetween thecollars on the shaft'20 and.-

the collars on the shaft 221, the cage'Si) also acting as Y paperholding means. The teeth ofthe cutterYV enter be- In Figures 10 andl5rthisV is 1 t tween the top of the cage 50 and the bottom of thecollar 60 and are thus held against bending.`

To make certain that the fold that is to be formed in the signature willextend longitudinally centrally through the row of cut or punched holes5, the cutter 40 is provided with a series of pins or knife edgeprojectingblades 100 between adjacent teeth 84. These are of a depthmerely sufficient to penetrate the stack of sheets and will form eithera pin hole or a short knife cut in the stack of sheets extendinglengthwise between adjacent slots 5. Each pin or knife edge blade isformed by cutting away the metal between adjacent teeth to a greaterdepth adjacent the leading and trailing edges 94--94 of each tooth thanat the center between teeth, so that at the center between teeth thereis left a small projection extending radially outwardly from theperiphery 103. This projection can then be milled or machined either toform a pin point, as in Figure 9, or to form a knife edge as in Figure12. In each case it is formed by removing metal at the edges of theprojection to form the opposite converging surfaces S-105. This forms aknife edge at 106 (Fig. 12) which knife edge may, if desired, be reducedto a point 106a as in Figure 9. As a result, the paper leaving thecutter will have formed therein a series of aligned slots 5 5 wherepaper has been removed and leaving hinged portions 6 6 between adjacentslots. The slots are aligned along the longitudinal center line 107.Each of the hinge portions 6 has a narrow cut or pin hole thereinlocated on the longitudinal center line 107. In the case of the cuttershown in Figure 9, this hole is in the nature of a pin hole or needlehole, indicated at 108 in Figure 13. This hole is centered on the centerline 107 and is of a width substantially less than the width of therespective slots 5 and does not involve the removal of any paper. In thecase of a cutter such as shown in Figure 12, the corresponding cut isshown at 108 and consists of a slit extending lengthwise on the centerline 107 andy of a very short length which is a fractional part of thedistance between adjacent slots 5. It may be, for instance, of a totallength of the order of one-third of the distance between adjacent slots5. This also involves no removal of paper.

After the paper leaves the cutter of Figure 4 it passes to the lastfold-forming apparatus on the folding machine. This fold is formed in aconventional manner, indicated diagrammatically in Figure 4. When thisfold is formed the page surfaces 115 and 116 (Fig. 4) are brought intofacing contact position by a fold wherein the paper is folded towardsrather than from the surface where the rotary cutter enters the paper.

The signature formed in the manner described above may then be stackedwith similarly formed signatures to form a book, in the manner describedin my pending application Serial No. 185,897.

Figure 13 shows an enlarged view of a portion of a sheet of paperimmediately after the slots 5 are formed and before folding. The fold isformed along the center line 107 which is the center line of the alignedrectangular slots 5. The slots 5 are more rough at their transversesides 109-110 than at their longitudinal edges 111, which facilitatesthe adhesion of adhesive that is to be used for securely holding thesignature and the individual sheets thereof in place. When a signatureof this type is folded the fold at the slot appears somewhat as shown inFigure 15, wherein the spaces which formerly were in the form of slotsin the unfolded signature result in a series of spaced notches at thefolded edge of the signature and wherein the outwardly extending tab 96is shown in rather exaggerated form. It is to be noted that in this typeof signature an auxiliary sheet, such as indicated at 112, may beinserted at any place in the signature, and a portion of the edgethereof will be exposed at the slots, so that glue which is later to beapplied will secure such inserted sheet in place. A stack of similarsignatures, as illustrated in Figure 16, is formed. The slots in eachsignature may be in line with or out of line with the slots of adjacentsignatures. The back of the stack of signatures of Figure 16 is thencoated with a suitable adhesive which penetrates the slots 5, theadhesive being indicated at in Figure 17, and then a book cover 116 iswrapped around the backbone to extend over the outer signatures toconstitute the cover of the book thus formed, the cover being adhered tothe stack of signatures by the adhesive 11S, as set forth in myapplication Serial No. 185,897.

Figure l8 shows a cross section through the end of a book in an editionbinding embodying the signatures of the present invention. In making ahard covered or edition binding book the signatures of the presentinvention are assembled and put through the usual forwarding operations,the backs coated with glue and overlaid with a backing paper sheet 122.'In the hard covered book two cover-receiving sheets of paper are foldedlengthwise as by a fold 127 and pasted one to the uppermost and one tothe lowermost sheet of the stack of signatures 10 in the usual manner,as by a narrow line of paste or other adhesive that extends lengthwisealong the top and bottom of the stack of signatures adjacent to the backthereof. Upper and lower cover sheets 129 and 130 are pasted to therespective sheets 125 which cover sheets are secured together by theusual sti book backbone that arches away from the folded edges of thesignatures 10 that constitute the book, as is usual in edition boundbooks. The book of Figure 18 is one intended for more durable servicethan is the book of Figure 17. The signatures of the books of Figure 17and Figure 18 are held together entirely by the glue or other adhesivethat penetrates the slots or notches 5 of the respective signatures andalso secures the pages of each signature together. The slots 5 are madeof suflcient Width so that when the signature is folded the notchesformed at the respective slots are of a considerable depth thereby toallow enough glue to enter into each notch adequately to secure thepages together. i

While the present invention has here been shown as applied to signatureswherein the slots 5 are rectangular and involve substantial removal ofpaper, it is within the purview of the present invention to apply theprinciples that involve forming the fold centering perforations 108 or108' in a signature wherein the glue enters an opening that is formedotherwise than rectangular, as in Figures 13 and 14. For instance, theperforations 108 or knife cuts 108 may be formed in correspondinglocations in a signature such as is shown, by way of example, in Figures4 and 12 of my co-pending application Serial No. 185,897, tiledSeptember 20, 1950, to which reference may be had. The center biasingperforations 108v or slots 108 may be formed in any signature wherein itis desired to make certain that the fold will form on a given line whereit might not otherwise form.

In compliance with the requirements of the patent statutes I have hereshown and described a preferred embodiment of my invention. It is,however, to be understood that the invention is not limited to theprecise construction here shown, the same being merely illustrative ofthe principles of the invention. What I consider new and desire tosecure by Letters Patent is:

l. A rotary cutting die for forming a linear series of perforations in astack of sheets of paper that are to constitute a signature, said diehaving a series of radially projecting punching teeth extendingoutwardly from the periphery thereof, the overall radial extent of eachtooth being of sulficient length to project well beyond the signatureand to eject the severed chips of the various paper layers from theformed perforation, and said die having sheet perforating projectionsbetween certain teeth, each having a substantially smaller correspondingtransverse cross-sectional dimension and radial extent relative to saidteeth, the teeth and the projections being in a cornmon plane whichpasses through the centers of the teeth and the centers of theprojections so that said projections produce cuts in the sheetsubstantially smaller than the blanks cut bythe teeth and centered alongthe central plane of said teeth.

2. A rotary cutting die .for forming alinear series of perforations in astack of sheets of paper that are to be folded along the series ofperforations to constitute a y signature, said die having a series ofradially projecting punching teeth extending outwardly from theperiphery thereof and having centers in acommon plane, each of ,lo

said cutting teeth being formed with a transversely 'extending leadingknife edge and a transversely extending trailing knife edge fspacedtherefrom, said edges being adapted toV penetrateV a stack of sheetsWith which it is in rolling engagement at spaced points therealong,.theintervening regions of each tooth between said edges being formed withradially inwardly converging opposed shearing edges for severing thematerial of the blank between the initial points of penetration inwardlyof the perforation to beforrned in opposite directions, the overallradiali.

extent of each tooth being of sufncient length as to eject the severedchips of the various paper layers from the Vformed perforation, and saiddie having sheet perforat-' ing projections between certain teeth andsubstantially narrower in a direction transverse of the f old line, andshorter in radial extent, than said teeth, the centers of theprojections being in the same common plane as that of the centers of theteeth to produce cuts in the sheet substantially. narrower than thewidths of the blanks cut by the teeth, and centered along the centralplane of said teeth.'

. 3. A rotary cutting die for forming a linear` series of perforationsin a'stack of sheets of paper that are to Vbe folded along the series ofperforations to constitute a sig-- nature, said die having a series ofradially projecting punching teeth extending outwardly from theperiphery VVthereof the overall radialextent of each tooth being ofsuicient length as to forciblyeject the severed chips of the variouspaper layers from the formed perforations, and said die having slittingprojections between adjacent teeth which slitting projections have adimension along the fold line which is a fractional part of the distancebetween teeth and have a radial extent smaller than said teeth, and arein a plane coincident with the central plane through said teeth forcutting the signature between theA perforations without substantialremoval of paper.`

4. A rotary cutting die for forming a linear series of perforations in astack Vof sheets of paper that are to be ciable dimension transverselyof.` a radial and a circurnfolded along the. series of perforations toconstitute a s ignature, said die having a series of radially projectingpunching teeth extending outwardly from the periphery thereof, theoverall radial extent of each tooth in a directiontransverse of the foldlineV being of sufcient length as to eject the severed chips of thevarious paper layers from theformed perforation, and said die havingVsheetengaging projections between .certain teeth land substan-V tiallyshorter in radial extent and narrower than'said` teeth in a directiontransverse Vof Vthe fold line, and said sheet-engaging projections andsaid punching teeth having their centers in a common radial plane, theprojections producing weakened lengths in the sheet substantiallynarrower than the widths of the perforations'cut` by the teethiandcentered along the central plane of said.`

teeth and extending lengthwise of and between perforations.

5. A rotatable cutting die -for forming a linear 'series i ofperforations in a stack of sheets offpaperithat are to be foldedalongthe series of perforations to constitute a signature, said dieVhaving a plurality of radially projecting teeth wherein at least one ofthe teeth has an appreierential line to form a perforation ofappreciable size in a direction transversely of the fold line and atleast one of the teeth being smaller in a radial direction and alsosmaller in a direction parallel to the axis of rotation of the die thanthe corresponding'dimension's of said one tooth, the teeth having theircenters in a common radial plane normal to the axis of rotation of thedieV whereby said smaller teeth forni a narrow perforation transverselyof the fold line.

' References Cited in the file of this patent UNITED'STATES PATENTS

